Vulcanizable patch



Aug. 27, 1935. H, w, SWTH ETAL 2,012,935

' VULCANIZABLE- PATCH Filed July 14, 1930 Patented Au 27,1935

UNITED STATES PATENT OFFICE- land, Md., assignorsuto Kelly-Springfield Tire Company, Cumberland, Md., a corporation of New Jersey Application July 14, 1930, Serial No. 467,842

9 Claims. (01.152-26) This invention comprises a new and improved type of preformed patch of the vulcanizable type' particularly adapted to be utilized in the repairing of ruptures in casings for automobile tires.

- The subject patch may be used for repairing a adhere tenaciously to the area covered thereby.

This class of patching may be practiced by cutting patch stock to fit the local'condition found, or, more expediently, to 'select the proper size and shape of a preformed'and fully prepared patch for the purpose.

The two usual types of preformed patches are, first; the self-vulcanizing style which is merely applied in an appropriate way to the ruptured surface and the gum coating thereafter vulcanizes of its own inherent properties without the application of the usual heat treatment and, second; the patch coated with unvulcanized but vulcanizable gum which requires the use of a repair vulcanizer properly to afllx it by local pressure and heat.

This class of preformed patch, at least conventionally, consists of a plurality of rubberized and semi-cured plies of fabric coated with an attaching layer of gum which is protected up to the time of use by a web of thin material, such as Holland. It is the usual practice to trim the edges of the largest ply of fabric sheer and even with the margin of the outer gum coating, whereby, when the patch is applied with gum and fabric margins exposed and even, there exists an excessively deep marginal stepoil. The soft outer gum coating being next to the surface under repair and the relatively harsh strength ply of fabric being on the reverse and exposed surface it is apparent that an inner tube, compressed and subject to a creeping movement against the raw and unprotected marginal edge of the exposed harsh fabric, will tend both to chafe and weaken the tube and, by creepage, induce a scuiling and loosening action along the patch margin. This combined evil isa decided disadvantage where I such patches are used.

job is found to consume too much time.

' Below fabric I4 is inwardly a suilicient distance I reinforcement to the relatively thin tapered Due to the advantage in effecting these minor repairs expeditiously the practice of cutting and fitting repair patch material by hand to suit eachfi is I now generally .found more economical and de- 5 cidedly faster for repairmen tq work with preformed patches supplied by the factory in a variety of sizes and shapes to fit various jobs; and it is to supply this demand with an improved 7 type of patch to which this invention is directed. 1.

Being cognizant of the defects of the conventional patches, this'inventioh is directed to the production of a preformed. patch of an improved form possessing the several advantages more particularly set forth herein and illustrated in 1| the accompanying drawing, in which:

Figure l. is a top view, partially broken away to show details, of a preferred form of the in-' vention. v

Figure 2 is an enlarged cross-sectional view so through the diameter (2-2) of Figure 1, showing a typical'application of the patch to repair a small rupture in a. tire casing. A fragments! cross-section of a casingalso is shown and a fragmental section of a typical pressure bag com- 3; pressing the patch against the inner surface of the casing is indicated in broken lines.

The specific patchshown (see Figure 1) comprises two plies of conventional cord fabric, rubberized, semiin such manner that the larger bottom fabric ll shall show a marginal projection beyond the smaller top fabric IS. The term top as used denotes the direction of iixationto a surface under repair. As shown in Figure 1, these plies preferably are arranged with their cords in v crossed relation. Completely overlaying the top a I3 is a layer of unvulcanized but vulcanizable gum l2 of such size that its margin projects beyond the margins of both I! and llfand this soft- 40 until use by a Holland top-ll. placed a layer of unvulcanized but vulcanizable gum of such size that its outer margin projects beyond the margin of M, preferably coincidingwith the marginal dimension of top gum i2. Such gum preferably extends t to aiford adequate gum is protected marginal portion of the patch, after vulcanization. This layer may, if desired, bein the form so of a ring such as l5, whichas shown in the drawing, extends inwardly past the marginal single ply portion of composite insertion l3 and it. These layers of gum are adapted to form an envelope or sheath encasing and projecting .out- I or partially-cured and assembled 1 wardly beyond the marginal edges of the rubberized cord fabric body. Bottom gum l5 also is temporarily covered by a protective sheet, such" as, for example, ring l6 of Holland.

The cross-sectional view, Figure 2, in diagram, illustrates one form of this patch in process of fixation to repair a break in a tire casing. The casing I1 is damaged at l8 and the area has been packed with a suitable vulcanizable gum shown as merged with the top gum I2, from which the Holland H has been removed. The conventional repair air bag [9 is shown in broken lines as it becomes compressed against the bottom of the patch in the process of vulcanization. with the parts in this position, the patch is subjected to a vulcanizing operation, and as this operation proceeds, the partially-cured insertions, the vulcanizable gum outer layers, and the backing gum at Hi, all will be vulcanized. The union thus formed between layer i2 of the patch and the tire casing, and among the several layers of the patch, is extremely firm and intimate, so that there will be formed what, in effect, may be regarded as a substantially homogeneous mass of vulcanized rubber encasing the plies of cord fabric. The patch formed in this manner possesses exceptional strength, and is admirably suited to give long and satisfactory service-life.

Figure 2 is intended to show the progressive unifying of the-margins of gums l2 and I5- as the material fiows and becomes molded during the heat of vulcanization under the squeeze of the bag l9. It is apparent that the marginal extremities of l2 and I5, being free flowing gum and unconfined, will unify and work into a fine bevel edge 20 as vulcanization progresses, avoiding any perceptible abruptness at this point. Also, the inner edge of the gum ring I! at 2| will become attenuated and practically merge with the exposed face of the bottom fabric ll.

The abruptness illustrated in Fflgure 2, at the margins, merely shows relative changes in con- 1 tour as the patch under vulcanization assumes and danger of scufling up of the effectivelyguarded fabric margins.

It is understood that the condition shown in Figure 2 and described implies the application of any conventional or desired repair vulcanizing appliances which are not illustrated.

While the typical example for this patch relates specifically to that requiring vulcanization for applying it is apparent that the invention includes the self-vulcanizing style embodying the novel features disclosed. Figure 2 could as well illustrate the working. into place of a self-vulcanizing patch wherein numeral I! would become the usual inner tubetWhere the term "unvulcanized is used without qualification the substance may be either unvulcanized self-vulcanizing or unvulcanized vulcanizable stock.

In applying the patch the usual preparation of the injured surface is implied, and the H01- land protector sheets are removed.

Since certain chan es may be made in the above product and different embodiments of the invention could be made without departing from the scope thereof, it is intended that all matter contained in the above description or shown in the accompanying drawing shall be interpreted as illustrative and not in a limiting sense.

It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.

Having described a preferred form of this invention, and reserving all variations that may come within the scope thereof, what we claim is:

1. A patch comprising a semi-cured body of strength insertion; a gum coating overlaying one surface thereof and marginally projecting therebeyond; and a marginal gum coating strip binding along the outer edge of the opposed surface of said body and marginally projecting therebeyond.

2. A patch comprising, in combination, an assembled composite structure including, multiple plyvulcanizable strength insertions; a vulcanizable top cover of sheet gum marginally overlapping said insertions; a ring element of vulcanizable gum marginally overlapping edges of said insertion on the surface opposed to that overlaid by the top cover, whereby in vulcanization to an objec-' tive surface the said insertion edges are completely enveloped by said gum elements.

3. A patch comprising, in combination, a partially-cured body of strength insertion, a gum coating overlaying one surface thereof and marginally projecting therebeyond, and an additional gum coating on the opposite surface of said body and extending outwardly and inwardly from the edges thereof.

4. A patch comprising, in combination, a body formed of partially-cured rubberized cord fabric, and an envelope of vulcanizable gum, covering at least one side and encasing and projecting outwardly beyond the margin of said body.

5. A patch comprising, in combination, a vulcanizable body having suflicient strength adequately to reinforce a damaged tire casing, and an envelope of plastic, vulcanizable gum covering at least one side and encasing the entire margin of said body, said gum being present at the margin in sufiiclent quantity tofiow under pressure to form a tapered gum margin merging without substantial abruptness into the surface to which the patch is aflixed.

6. A patch comprising, incombination, a body formed of a plurality of plies of rubberized cord fabric so disposed and arrangedthat fewer plies are present at the margin than at the central portion of said body, a' layer of vulcanizable gum extending over one side of said body and projecting marginally therebeyond, and a layer of protecting material on the opposite side of said body and projecting marginally therebeyond, the marginally projecting portions of said gum and'said protecting material meeting to encase the edges of said plies. A

7. In a patch, the combination including a body formed of a plurality of plies of partially-cured rubberized cord fabric so disposed and arranged that fewer plies are present at the margin than at the central portion of said body, and a layer of vulcanizable gum extending Overon'e' side of said body and projecting marginally therebeyond,

, and means on the other side of the body cooperating with said layer to encas'e the edges of said plies.

8. In a casing patch of the character described, the combination of a patch structure made up of ply material and providing an edge in which reinforcing is exposed; and a sealing strip placed along said edge and having a portion formed to extend across said edge and cover the ends of reinforcing exposed therein.

9. A casing patch of the character described, in-

cluding: a patch structure comprising a ply member having an exposed edge; and a sealing layer of rubber material on the patch structure in a position to overlap said edge, said overlapping portion being formed to extend across said edge.

rumor-n w. sm'rn. JOHN E. MccAR'rY 

